Researchers at the University of Bonn have discovered that a photon Bose-Einstein condensate, an exotic quantum state where particles of light merge into a “super photon,” abides by a fundamental theorem of physics. By cooling photons using dye molecules, researchers were able to observe the super photon flickering like a candle. This allowed them to test the validity of the regression theorem, which predicts how systems respond to perturbations. The study was published in the journal Nature Communications.
In their experiments, researchers filled a container with a dye solution and excited the molecules with a laser, creating photons that bounced between reflective surfaces. As the particles repeatedly collided with the dye molecules, they cooled down and condensed into a quantum gas. This quantum gas exhibited fluctuations in the number of photons, causing it to flicker like a candle. Researchers used this flickering to test the regression theorem, comparing the response of the super photon to controlled perturbations and random fluctuations.
The regression theorem predicts that systems will respond to perturbations in the same way they fluctuate without perturbations. Researchers were able to illustrate this phenomenon by introducing perturbations to the super photon, observing its response before returning to its initial state. This demonstrates that the theorem also applies to exotic forms of matter such as quantum gases. The findings have implications for fundamental research with photonic quantum gases, allowing researchers to study unknown properties under controlled conditions.
The study showed that even with strong perturbations, the super photon responded in the same way as random fluctuations, demonstrating the validity of the regression theorem in nonlinear cases. This discovery has implications for understanding the behavior of photonic materials comprised of multiple super photons at their core. By studying how super photons respond to controlled perturbations, researchers can gain insights into the behavior of these novel materials and explore their properties in a controlled environment. This research can lead to advancements in the understanding of quantum gases and their potential applications in various fields.